For most people who are considering moving to Windows 7, October 22 is D-Day. On that date Microsoft's newest operating system lands on store shelves, both as a shrinkwrapped upgrade and preinstalled on new PCs. For some folks, though, D-Day has already arrived. Microsoft has issued the final RTM (release to manufacturing) version of Windows 7 to large companies that buy Windows via volume licenses, as well as to IT pros who belong to its Technet service. The Windows Vista era is officially drawing to a close--although you could argue that it never really quite started--and the Windows 7 one is under way.

And that promises to be a good thing, whether you're a satisfied Vista user, a disgruntled one, or a Windows XP holdout who has been waiting for something better. Windows 7 feels like an anti-Vista: Unlike that OS, for instance, it doesn't try to dazzle you with flashy new visual effects. With the removal of Vista applications such as Photo Gallery and Movie Maker, Win 7 actually does fewer things than Vista did. Even its unprepossessing name is a change from the epic-sounding monikers that began with the unfortunate Windows Millennium Edition.

But Windows 7's lack of glitz is a huge part of its appeal. Unlike the increasingly chaotic and annoying Microsoft OSs that preceded it, Windows 7 is designed to stay out of your way so that you can get stuff done. It smartly addresses Windows annoyances both new (User Account Control) and old (the system tray). And the final version I've been using seems to realize the promise of the rough drafts we started testing last October.

Windows 7 isn't without its warts, but I haven't been so impressed by a new Microsoft operating system since Windows 2000 debuted close to a decade ago. Here's a quick look at some of its best features, a few drawbacks, and areas where reserving judgment makes sense. (Much more PC World coverage is on its way, including an in-depth review with speed benchmarks, upgrade tips, and Windows 7 system reviews.)

The Good...

The OS is less piggish: One of the many regrettable things about the initial version of Windows Vista was that its signature feature--the splashy Aero environment--was too much of a resource hog to run well on many early-2007 PCs (even those that had been promoted as Vista-capable). The PC World Test Center hasn't benchmarked the shipping version of Windows 7 yet--stay tuned--but all signs point to this OS being sprightly enough to perform decently on all current systems, including those allegedly underpowered, pint-size machines known as netbooks.

The taskbar has been reinvented: It's amazing how little the taskbar and its system tray have changed since Windows 95. In Windows 7, they both undergo sweeping, long-overdue makeovers. For the most part, the results are extremely pleasing.

Windows 7's new taskbar sports better thumbnail previews, context-sensitive Jump Lists, and other features that help speed up the management of apps and windows.The new taskbar's default style does away with text labels and relies solely on program icons, therefore making better use of screen space. Its thumbnail previews--an improvement over Vista's--work well even when you have multiple windows open for one application. And the new Jump Lists feature gives you right-click access to context-sensitive menus of options (such as the ability to play shuffled music in Windows Media Player) even before you've launched an application. Even the nub on the right edge of the taskbar, which you can click to reveal the desktop, is a welcome, subtle enhancement. (One taskbar quibble: The border around running apps in the taskbar isn't a clear enough cue to distinguish between them and those that aren't currently active.)

The new system tray (aka the notification area) gives you fine-grained control over the applets that live there and how much they can pester you.The system tray--which is officially called the notification area, although I don't know anybody who calls it that--is no longer one of Windows' most aggravating "features." When you install new applications, any associated system-tray applets are cordoned off in a holding pen, where they can't clutter up the tray and can't use word balloons to pester you with information that you may or may not care about. You can also choose to have an applet appear in the system tray but in bound-and-gagged form, so it can't pop up messages. Microsoft has also dramatically reduced the volume of distracting messages from Windows itself, courtesy of Action Center, which queues up system alerts so that you can check them out at your convenience.

The famously annoying User Account Control security feature now lets you specify just how obnoxiously it should alert you to potential security problems.UAC is now tolerable: Windows Vista introduced User Account Control, which tries to warn you of attempts by viruses and other malware to tamper with your system. But it essentially has two settings: So Annoying You Click Without Thinking, and Off. In Windows 7, you get two intermediate settings that alert you only if a program changes settings, with or without the melodramatic screen-dimming effect. This new version is such a reasonable approach that it's even more mysterious how Microsoft could have botched the Vista version so badly.

Libraries collect your files: For years, Microsoft has tried to train Windows users to store all of their personal files in one place, helpfully providing a folder named My Documents for that purpose. Many of us blithely ignore the suggestion and store stuff willy-nilly around our hard drives. A new feature called Libraries splits the difference by giving you virtual folders for documents, music, photos, and videos that combine the contents of whichever folders you specify into one unified view. The Pictures Library, for instance, can show all your photos even if they're stored in a dozen different places. Still, there's room for improvement--Libraries would be even more useful if they were integrated with the existing Saved Searches feature, which creates another, separate form of virtualized folder.